1. Field of the Invention
The present invention is directed to the field of nondestructive testing and more particularly to the area of inspecting ultrasonic welds in thermoplastic material.
2. Description of the Prior Art
During the formation of parts from thermoplastic materials, it is common to join separate pieces by utilizing ultrasonic welding processes. However, the common forms of evaluating the quality of the weld employ destructive testing techniques. Pressure or pull tests are employed which determine the fracture point of the weld. Due to the nature of any destructive test, statistical sampling techniques are necessitated, since each tested part is destroyed.
While the use of ultrasonic welds and statistical samplings have, in general, provided manufacturers with a predictable yield rate, it is more desirable to provide an automatic nondestructive technique whereby 100% inspection can be made of the ultrasonic weld in thermoplastic material to thereby provide a quality sort of the welded parts.